Attach the iPhone 11 motherboard to the PHONEFIX PCB Holder Fixture, remove the shield cover, and then we need to separate the iPhone 11 motherboard.
Use hot air gun to heat the iPhone 11 motherboard for a while, and then use tweezers to remove the upper layer board.
Observing the iPhone 11 motherboard, we can see that the iPhone 11 baseband CPU is Intel version, the model is 9960. As we know, the model for last iPhone is 9955.Although the IC has changed, but the iPhone signal is not much different from the previous iPhone.
Test the iPhone 11 upper layer logic board to check if it's same as the previous iPhone can be turned on by a single logic board. After testing, yes, it can, just be baseband.
The iPhone 11 uses the fastest A13 chip，put iPhone 11 motherboard under a Trinocular Integrated Microscope, and then use hot air gun and BGA graver to remove the iPhone 11 CPU. Insert a BGA remove blade start from "3", and carefully move it to "1", but don't approach the "A". Try to pry the iPhone 11 CPU, and then remove it.
Apply some solder paste to the iPhone 11 CPU solder pad to remove the glue, and then remove the glue on the iPhone CPU.
Send date to factory to make the PCB holder fixture and BGA reballing stencil, and then we can re-solder the iPhone CPU. Use DES H95 hot air gun to install the A13 back the motherboard,and then assemble the iPhone 11 motherboard.
Now assemble the iPhone 11, and test it, the iPhone 11 works perfectly.